Vat dyestuff and process of making same



Patented June 15, 1926.

UNITED STATES WIILHELM ECKERT AND HEINRICH GREUNE, OI HOGEST-ON-THE-MAIN, GERMANY.

'VA'I DYESTUIF AND PROCESS OF MAKING SAME.

No Drawing. Application filed July 17, 1925, Serial No. 44,369, and in Germany 11113? 21, 1924.

We have found that new valuable vat d estuffs are obtained by condensing the thalenetetracarboxylic acid used as parent product is a perfectly white body to which, even if it is transformed into the di-imide, cannot be imparted the characteristic properties of a dyestuflr'.

The following example illustrates our invention the arts being by wei ht:

10 parts of the dianhydride o the 1.4.5.8-

'- naphthalenetetracarboxylic acid are heated in 50 parts. of nitrobenzene with 20 parts of ortho-phenylenediamine until the prodnot resulting from the reaction is entirely separated. This product is filtered off by suction and washed with alcohol until the excess of ortho-phenylenediamine is entirely eliminated. The new (1 stuff forms, when dry, a bright red pow er. which dissolves in concentrated sulfuric acid to a yellowishbrown solution. It gives a green vat which dyes cotton the. same color which, when the material is exposed to the air, changes to a brilliant red tint with a yellow hue.

If for the ortho-phenylenediamine is substituted 4-chloro-1.2-diaminobenzene and the further operations are carried out as above.

indicated, a dyestufi is obtained which dyes cotton from a green vat a green tint which, when the material is ex osed to the air, changes to a bright red 'sh brown shade of excellent fastness.

F r o m 4-nitro-12-diamin0benzene and 1.4.5.8-napthalenetetracarboxylic acid or its anhydride a dyestuif is obtained as a brown powder,'which dissolves in concentrated sulfuric acid to a yellow solution ith an intense green fluorescence. The vet I consisting in con ensmg prepared therefrom is of a green color and dyes cotton the same color which, when the material is exposedto the air, changes to a rey to black tint.

nthe same manner there may be condensed instead of the bases themselves their salts, particularly the hydrochlorides, with naphthalene-1.4.5.8-tetracarboxylic acid or its anhydride. I

Instead of condefising. a naphthalene- 1.4.5.8-tetracarboxylic acid halogenated or not, with a halogenated ortho-phen lenediamine substituted or not, the formed condensation products partially containing or not contaming halogen, may afterwards be halo enated. This halogenation may be effected by suspending the condensation product in a diluent, such as nitrobenzene, and introducin for instance a gentle current of chlorine into the mass, while heating to about 160-1 80 C- Finally the mass is isolated in the usual manner.

The chlorinated product thus obtained dissolves in concentrated sulfuric acid with a red-color and dyes cotton from a green vat a reddish-brown tint.

As the 1.4.5.8-naphthalenetetracarboxylic acid reacts in essentially the same manner asthe anhydride, we understand by .the term 1.4.5.8-naphthalenetetracarboxylic acid, used in the following claims, not only this acid itself but also its anhydride, and by an ortho-diamine we understand also the salts of it. I

The condensation may also be effected in absence of a solvent or diluent with the same result by melting together for a short time both components.

We claim:

1. Process of a 1.4.5.8-naphthalenetetracarboxylic aci with an orthodiamine. I

2. Process of (preparing vat dyestuffs, consisting in con diamine in presence. of diluents.

3. Process of preparing vat dyestuffs, com

reparing vat dyestuffs,

nally ensing a 1.4.5.8-naphthalenetetracarboxylic acid with an ortho-' sisting in condensing 1.4.5.8-naphthalenetetracarboxylic acid with a nitrated 1.2- 1 diaminobenzene.

4. Process of' reparing vat dyestuffs, 5 consisting in con ensm a 1.4.5.8-naphtha lenetetracarboxylic aci with an orthodiamine and halogenating the condensation product. a

5. As new products, the vat dyestufis of 10 the following composition:

6. As a new roduct,

the vat dyestufi' of the following ormula: v

. A OO O as v v \/\o or /\JO p o v being a red powder, soluble in concenv o trated sulfuric acid with a ellowiih-grown 4 color, giving a green vat, mm W 1c cotton is d' ed after exposure to the air a brilliant ye lowish-red. In testimony whereof, we aflix our sigwherein X re resents hydrogen or an natures. t. 6 substituent and a hydrocarbon substitutec DR. WILHELM ECKERT. or not. 1 DR. GREUNE. 

